Electrical Safety Heater

ABSTRACT

An electrical safety heater apparatus includes an upper metal hot casing and a lower non-flammable electrically and thermally insulating lower section. The apparatus further includes a standard tungsten incandescent or halogen bulb or multiple bulbs and a removable crown top of the heater.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an electric space heater for domestic and office use that uses a conventional electric tungsten incandescent or halogen light bulb or multiple bulbs as the heat source to passively heat a chamber which in turn radiates the heat to the surrounding area.

2. Background of the Invention

Space heaters augmenting the main heating system have long been used to warm odd or hard to heat areas of a home or office.

Kerosene and propane heaters, while effective, can be obvious fire hazards, produce fumes, smoke, CO and C02 gas and can deplete the oxygen in a room. These heaters need to be refilled often and for safety reasons must be turned off before leaving the area or going to bed.

A variety of electric space heaters using lamps or light bulbs as a heat source have been disclosed which include the use of such things as reflective film, reflective coating, a hair dryer and as a water heater. The conventional electric space heaters are all rather expensive to operate, as the lowest power at which any is at all effective is at least 500 watts and all need to feature settings up to 1500 watts. This is a great drain on current.

Most electric space heaters are complicated by motor driven fans to force the heated air about. This makes them noisy and robs them of heating efficiency by needing to convert a portion of their wattage (heat) to mechanical energy in the fan motors.

The complication of motors requires overheat/overcurrent cutoff switches/circuitry in case the moving parts seize up, which happens. No cutoff switch is fail-safe, which presents a fire/shock hazard.

Electric space heaters that do not feature motors still require the same overheat/overcurrent switches/circuitry subject to the same failures.

Most electric space heaters project their heat in a small specific direction or quadrant (as in the case with oscillating heaters) which necessarily means they produce high heat in a small area sufficiently to produce burns to any part of the body that is allowed to touch the grille of the heater or linger too close to it.

The oil-filled heaters that look like the old-time hot water/steam radiators don't require motors, and are an attempt to radiate heat 360°, but even with their large surface area, they fall way short in this. Except for one end surface, all the other heating surfaces face each other with the result that the heater must cycle off and on frequently to prevent overheating itself. This makes it expensive to operate because of the off and on power surges.

The heat produced is felt above the heater, but except for that one end very little heat radiates out from the sides.

These heaters are also unattractive to put in the middle of a room when heat is wanted there.

SUMMARY OF THE INVENTION

As tight and as ultra-insulated as modern construction has become and with techniques and materials for up-insulating and eliminating drafts in older construction, electric space heaters need not run on such high power as the current herd of electric space heaters use.

“Heat pumps” are now widely used for domestic heat systems but on wintry days a bit of help is often required. The present invention is a “safety heater” that uses a conventional light bulb or bulbs as the heat source.

This heater has the advantages of being simple, quiet, clean and safe, conserves energy, is effective, versatile, and exudes a warm ambiance in any room it is heating.

The electrical safety heater of their present invention includes an upper metal casing having a top and bottom end, a lamp, a non-flammable lower casing having a top and bottom end, a lamp receptacle having a cord suitable for connection to an electrical power source. The bottom end of the upper metal casing is connected to the top end of the lower casing and the lamp or light bulb is situated within the upper casing and the lamp receptacle is situated within the lower casing. The heater of the present invention has a lower casing made of material from a group consisting of ceramic, ferro cement and/or plastic. It preferably has a base connected to the bottom end of the lower casing and made of the same material as the lower casing. Preferably the legs attach to the base and a crown top member is attached to the top end of the upper metal casing. The crown top member is preferably removably connected. The upper metal casing may be a single piece or may include at least one additional upper member removably connected to the crown and connected to the top end of the upper metal casing. The electrical heater includes an aperture suitable for a cord to pass through within the lower casing to outside of the lower casing and preferably through an aperture lined with a grommet. The heater may contain simply one or multiple lamps and can further include a wall switch connected to the cord for turning the heater on or off. The cord is connected to a standard electrical outlet or it can also be connected to a battery suitable for providing power to the lamp. The lower casing is preferably non-flammable and electrically and thermally insulating.

The heater of the present invention has a number of advantages, it is simple, quiet, effective, safe, clean, easy to keep clean, is versatile, conserves energy and contributes positively to the ambience.

The “safety heater” is simple because the only moving part is the switch to turn it on, or a selector switch in the multiple bulb models. There are no noisy fans. Fans also blow dust around along with the heat.

The standard tungsten incandescent bulb and its younger cousin the halogen bulb remain 100% efficient as heat sources. They are also effective (to illustrate the term “effective”, the compact fluorescent light (CFL) does not produce enough heat to be effective in this application).

The tungsten bulb is at least 33% more effective than a comparable halogen bulb, as it produces that much more heat.

The tungsten/halogen bulb is safe. The tungsten bulb has been safely used in houses and offices for over 130 years, and the more recent halogen bulb is the same configuration, with the glass tougher. These bulbs as heat sources have no open flame for fire hazards, produce no smoke, fumes, carbon dioxide and carbon monoxide gas, nor will they deplete the oxygen in a room.

The heater is hot enough to heat: not hot enough to burn. It's large radiating area, heats all 360° around and makes high temperatures unnecessary, so is safe with small children and animals in the house (cats and dogs won't burn their fur). This is an ideal heater where there are inside birds which are prone to respiratory problems as with humans. A heater employing these bulbs as heat sources may safely be left on when leaving the house or area or going to bed. This is especially comforting for those who sometimes feel the need to recheck things just turned off. With the safety heater, it does not matter.

There are no nooks and crannies to catch and hold dust. The crown of the heater is designed to keep dust from settling on the rest of the surface and cleans with a simple swipe. Therefore there is no smell of burning dust when it is turned on as with other heaters.

The heater uses no more energy than leaving a couple of light bulbs on. Normal operation is-turn it on and leave it on. There are no costly electrical surges from cycling off and on.

Multiple bulb models have a selector switch for desired heat range. In the single bulb models one can always replace a higher wattage bulb with a lower wattage bulb if desired.

The small conical section heaters described later make fine foot warmers as in a cold bathroom or a favorite reading chair or even under the desk in a cold office.

On all models the flat crown surface is ideal for keeping your coffee or tea hot and can even simmer oatmeal perfectly without it sticking to the pot.

One can set a pan or kettle of water on top and you have a fine winter humidifier as well.

Most rooms in houses and offices these days are heated from the periphery: that is, registers are blowing some heat pump's dust-laden air at your ankles from the baseboards around a room. Not so with the safety heater. Close the door on the miserable winter weather and turn to feel the quiet, cozy warmth emanating from the middle of the room, reminiscent of the steady, grand old heat that once came from a pot belly stove but without the bother of stoking, smoke, and ashes to dump.

The soft glow of light from beneath the crown indicates it is on, but is also a perfect night light.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the electric safety heater apparatus.

FIG. 2 is a top view from the perspective view 2 as denoted on FIG. 1 of the electric safety heater without the lamp installed and without the upper casing installed.

FIG. 3 is a bottom view from the perspective view 3 as denoted on FIG. 1 of the electric safety heater without the base installed.

FIG. 4 is an exploded view of one embodiment of the electric safety heater apparatus.

FIG. 5 is a side view of the electric safety heater apparatus having multiple light bulbs.

FIG. 6 is a side view of the electric safety heater apparatus, with a conical shaped upper metal casing.

FIG. 7 is a side view of the electric safety heater with an additional upper member and an overhanging crown top.

FIG. 8 is an exploded view of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

The heater, to borrow gas turbine phraseology, has a “hot section” and a “cold section”.

The lower casing 12 “cold section” shown in FIGS. 1 and 4-8 consists of a wide, low (around 8″ tall) enclosed base of dense and durable, electrically and thermally insulating, not-flammable material such as pottery, ceramic or Ferro cement. The shape and density of the base is chosen to provide a low stable center of gravity for the heater. Three or four equally spaced rubber button feet or legs 26 provide a solid stance on any even or uneven floor surface. If there are four feet, two adjacent feet will be screw-adjustable for leveling.

A suitable house current power cord 20 passes through a grommet 28 into the low periphery of the base as shown in FIG. 4 and is connected inside to an on/off switch 30 shown in FIG. 1 or an on/off/selector switch 34, as shown in FIG. 5, with both “hot” and “common” leads, made with suitable high temperature wiring to the porcelain lamp receptacle(s) 22. At the top of the cold section enclosure is a hole or holes large enough for the neck of the porcelain lamp receptacle(s) 22 to protrude through, and each lamp receptacle 22 is through-bolted to the underside of the lower casing top end 40 of the cold section enclosure, with the neck sticking up through the hole and electrical connection screws facing downward, in towards the cold section enclosure. In this configuration, the heat necessarily from the base of the heating bulb 16 is safely dissipated through the porcelain base of the lamp receptacle 22 to the top of the cold section and dissipates down the sides, leaving the electrical connections to the lamp receptacle 22 very cool in comparison as shown in FIG. 1. None the less, for safety, all electrical connections to the porcelain lamp receptacle 22 are made with high temperature wire, as stated before, with suitable slack for expansion and contraction.

In a configuration with two or more lamps FIG. 5, (the purpose being to retain at least some reduced heating capability if one or more lamps 16 fail) the porcelain receptacles 22 are spaced so as not to overlap one another to ensure safe, even heat dissipation. Multiple lamps are wired in parallel so one failed lamp will not turn out the others. Again, for safety, all electrical connections to and between the lamp receptacles 22 are made with high temperature wire with suitable slack for expansion and contraction.

The “Hot Section”

Fastened on top of the cold section base is a chamber which re-radiates the heat from the bulb(s) to the surrounding area. This is the upper metal casing 10 “hot section”, shown in FIGS. 1 and 4-8. It is capped by a flat metal cast or stamped crown with its periphery turned down at an angle all around, much like a pie pan turned upside down. This crown 18 must be readily removable to facilitate changing a burned out bulb(s). The crown 18 and hot section chamber 10 are formed of a high thermally transmissible metal such as aluminum, anodized to a dark color on the inside to absorb the heat of the bulbs which is re-radiated out. Enough space is provided around and above the heating bulb(s) so that the hot section temperature will not diminish the bulb's normal working life. Findings are reflected in the table below:

Hot Section Chamber Space Over Wattage Value Cu. Ft. Diameter Bulb(s) 150 .13 6″ 4″ 200 .25 8″ 8″ 300 .34 8″ 8″ 400 .52 12″  6″

The simplest shape for the hot section is cylindrical and assuming an 8″ high “cold section” base, cylindrical heaters are from 16-20″ tall as shown in FIGS. 1 and 4.

The hot section 10 may also be an inverted conical section as shown in FIGS. 6-8 or trapezoidal section, the sides of which radiate the heat downward, especially efficient and effective for warming feet and floors as is nice in a bathroom on a cold morning, or a cold office.

The increased volume at the top of an inverted cone/trapezoidal section allows a heater with a lower profile. Since hot air rises, the lower the profile the more effective the heater. This hot section shape yields a heater from 12-14″ tall in 150 watts for example.

The shape of an effective hot section 10 as an inverted cone on the bottom joined to a narrow conical section, right side up, 44 is shown in FIGS. 7 and 8. This also radiates heat downward and the air rising around the joint between the two sections forms eddies which mixing, help to heat the air at some distance from the heater. This hot section shape also yields a heater of 12-14″ tall in 150 watts. The crown 18 of this type of hot section requires a short lip or ring 56 protruding into the chamber to keep the crown keyed in place, yet still leave it easily removable for changing bulbs. In the two-piece hot section, the upper metal casing top end 36 is connected to the additional upper member 44 and the upper metal casing bottom end 38 is connected to the lower casing top end 40 as shown in FIG. 8. The lower casing bottom end 42 has mounting bosses 32 for connection to the base 24 also as shown in FIG. 8.

The crowns 18 of all the aforementioned types of chambers overhang the chambers enough to make an effective, easily cleaned dust cover to keep dust off the hot section sides and to form eddies as the surrounding hot air rises along the sides. For safer heating the crown 18 must fit loosely enough so if the heater is ever upset, the crown 18 will flop off allowing the heat in the hot section 10 to dissipate.

Any of these various hot section chamber 10 shapes may be used with any single or multiple bulb configurations as long as enough volume and head space is provided when increasing to higher wattage.

FIGS. 2 and 3 show the inside of the heater and show the periphery of the receptacle flange 48, the bolts for fastening the lamp receptacle 50, the hole 52 in the top surface of the lower casing 12 and the electrical connectors 54.

A stout wire handle 14 is provided to facilitate moving the heater, though in practice once the optimum spot for the heater is found it is rarely moved except to clean around it. 

I claim:
 1. An electrical safety heater comprising: a. an upper metal casing having a top and bottom end; b. a lamp; c. a non-flammable lower casing having a top and bottom end; d. a lamp receptacle having a cord suitable for connection to an electrical power source; e. said bottom end of said upper metal casing connected to said top end of said lower casing; and f. said lamp situated within said upper casing and said lamp receptacle situated within said lower casing.
 2. The electrical safety heater of claim 1 were in said lower casing is made of a material or group consisting of ceramic, ferro cement, and plastic.
 3. Electrical safety heater of claim 1 further comprising a base connected to said bottom end of said lower casing and comprised of the same material as said lower casing.
 4. The electrical safety heater of claim 3 further comprising legs attached to said base.
 5. The electrical safety heater of claim 1 further comprising a crown top member attached to said top end of said upper metal casing.
 6. The electrical safety heater of claim 5 wherein said crown top member is removably connected at said top end of said upper metal casing.
 7. The electrical safety heater of claim 6 wherein said upper metal casing includes at least one additional upper member removably connected to said crown and connected to said top end of said upper metal casing.
 8. The electrical safety heater of claim 1 wherein said lower casing further includes an aperture suitable for a cord to pass from within said lower casing to outside of said lower casing.
 9. The electrical safety heater of claim 8 wherein said aperture is lined with a grommet.
 10. The electrical safety heater of claim 1 further comprising multiple lamps.
 11. The electrical safety heater of claim 1 further including a wall switch connected to said cord for turning said heater on and off.
 12. The electrical safety heater of claim 1 wherein said cord is connected to a standard electrical outlet.
 13. The electrical safety heater of claim 1 wherein said cord is connected to a battery suitable for providing power to said lamp.
 14. The electrical safety heater of claim 1 wherein said the lower casing is non-flammable and electrically and thermally insulating. 